The Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units (MFMU) Network was created in 1986 to conduct clinical research studies in obstetrics and perinatal medicine. The Network consists of a number of major academic clinical centers, a data coordinating center, and the Institute itself. The research) studies, principally randomized trials but also observational studies, are aimed at reducing maternal, fetal and infant morbidity related to preterm birth, fetal growth abnormalities and maternal complications and to provide the rationale for evidence-based, cost- effective, obstetric practice. The data coordinating center is a critically important part of this collaborative effort. The overall purpose of the coordinating center is to make sure that the studies are designed to minimize bias, are conducted with integrity, and the results analyzed and interpreted appropriately to ensure the validity of the conclusions. The coordinating center is responsible for assisting the clinical investigators with developing the protocol, making sure that regulations regarding protection of human subjects are followed, creating data forms and a manual of procedures so that the data are collected accurately and training the clinical center staff to follow the procedures. The coordinating center provides a data entry and management system and monitors the data, as well as adherence to the protocol and retention of the study subjects. For randomized trials, the coordinating center creates the randomization system, prepares interim reports for the independent Data and Safety Monitoring Committee that is responsible for the safety of the patients on the trial, and reports for the FDA, if that agency is overseeing a trial. The coordinating center conducts the final analysis of the data and assists the clinical center investigators with the preparation of publications, and coordinates sharing of datasets and resources per NIH policy. The coordinating center facilitates communication among the centers and NIH, and provides a secure internal website for sharing information, in addition to arranging meetings, conference calls and videoconferencing. Finally the coordinating center is in charge of obtaining supplies and services, such as study drug and screening laboratories, necessary for the conduct of the studies, and for making payments to the centers associated with recruitment and follow-up of the study subjects.